Trump's phony yet legal border emergency

California et al. argue that Trump’s end run around the legislative branch’s exclusive authority to appropriate taxpayers’ money “violates the separation of powers doctrine.” But if so, it’s a violation that Congress itself seems to have authorized.

Can Congress do that? The nondelegation doctrine, a long moribund principle that prohibits one branch of government from passing off its responsibilities to another, suggests Congress cannot.

The Supreme Court has not invalidated an act of Congress as a violation of the nondelegation doctrine since the New Deal. But the justices recently heard a case that invites them to put some teeth into the rule, which historically has been invoked far more often than it has been enforced.